Publication Date:
2015-06-20
Description:
G protein-coupled receptors (GPCRs) relay diverse extracellular signals into cells by catalyzing nucleotide release from heterotrimeric G proteins, but the mechanism underlying this quintessential molecular signaling event has remained unclear. Here we use atomic-level simulations to elucidate the nucleotide-release mechanism. We find that the G protein alpha subunit Ras and helical domains-previously observed to separate widely upon receptor binding to expose the nucleotide-binding site-separate spontaneously and frequently even in the absence of a receptor. Domain separation is necessary but not sufficient for rapid nucleotide release. Rather, receptors catalyze nucleotide release by favoring an internal structural rearrangement of the Ras domain that weakens its nucleotide affinity. We use double electron-electron resonance spectroscopy and protein engineering to confirm predictions of our computationally determined mechanism.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dror, Ron O -- Mildorf, Thomas J -- Hilger, Daniel -- Manglik, Aashish -- Borhani, David W -- Arlow, Daniel H -- Philippsen, Ansgar -- Villanueva, Nicolas -- Yang, Zhongyu -- Lerch, Michael T -- Hubbell, Wayne L -- Kobilka, Brian K -- Sunahara, Roger K -- Shaw, David E -- P30EY00331/EY/NEI NIH HHS/ -- R01EY05216/EY/NEI NIH HHS/ -- R01GM083118/GM/NIGMS NIH HHS/ -- T32 GM008294/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2015 Jun 19;348(6241):1361-5. doi: 10.1126/science.aaa5264.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉D. E. Shaw Research, New York, NY 10036, USA. ron.dror@deshawresearch.com david.shaw@deshawresearch.com. ; D. E. Shaw Research, New York, NY 10036, USA. ; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA. ; Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109, USA. ; Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA. ; D. E. Shaw Research, New York, NY 10036, USA. Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA. ron.dror@deshawresearch.com david.shaw@deshawresearch.com.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26089515" target="_blank"〉PubMed〈/a〉
Keywords:
GTP-Binding Protein alpha Subunits, Gi-Go/*chemistry
;
GTP-Binding Protein alpha Subunits, Gs/*chemistry
;
Guanine Nucleotide Exchange Factors/*chemistry
;
Humans
;
Models, Chemical
;
Molecular Dynamics Simulation
;
Protein Structure, Secondary
;
Protein Structure, Tertiary
;
Receptors, G-Protein-Coupled/*chemistry
;
Signal Transduction
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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